Celtic boss Ronny Deila says keeping his best players will take priority over acquisitions in the transfer window.
Chelsea striker Fernando Torres is understood to be set for a return to Atletico Madrid, according to Sky sources.
Bolton have completed the loan signing of Norwich midfielder Jacob Butterfield.
The 22-year-old will spend a month at the Reebok Stadium and is Dougie Freedman's first signing as Wanderers manager.
Butterfield damaged his anterior cruciate ligament while playing for Barnsley against Leeds last New Year's Eve and moved to Norwich this summer despite his ongoing recovery from surgery.
The England Under-21 international has made two appearances for the Canaries this term, both in the Capital One Cup victories over Doncaster and Tottenham.
He is available to make his Bolton debut in the npower Championship trip to Blackpool this weekend.